been there, tried that. ended up just using some basic css rules to keep it from crawling apart to 1080p :(

  @namespace url(http://www.w3.org/1999/xhtml);
  @-moz-document domain("news.ycombinator.com") {
    body > center > table {max-width: 960px;}
    .default {padding-right: 22px;}
    textarea {width: 100%;}
    form {padding-right: 18px;}
  }

= less eye strain